name stringlengths 5 6 | title stringlengths 8 144 | abstract stringlengths 0 2.68k | fulltext stringlengths 1.78k 95k | keywords stringlengths 22 532 |
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628040 | Efficient Cost Models for Spatial Queries Using R-Trees. | AbstractSelection and join queries are fundamental operations in Data Base Management Systems (DBMS). Support for nontraditional data, including spatial objects, in an efficient manner is of ongoing interest in database research. Toward this goal, access methods and cost models for spatial queries are necessary tools f... | INTRODUCTION
Supporting large volumes of multidimensional (spatial) data is an inherent characteristic of modern
database applications, such as Geographical Information Systems (GIS), Computer Aided Design (CAD),
Image and Multimedia Databases. Such databases need underlying systems with extended features (query
langua... | query optimization;spatial databases;access methods;r-trees;cost models |
628041 | The Effect of Buffering on the Performance of R-Trees. | AbstractPast R-tree studies have focused on the number of nodes visited as a metric of query performance. Since database systems usually include a buffering mechanism, we propose that the number of disk accesses is a more realistic measure of performance. We develop a buffer model to analyze the number of disk accesses... | Introduction
R-trees [3] are a common indexing technique for spatial data and are widely used in spatial and multi-dimensional
databases. Typical applications include computer-aided design, geographic information
systems, computer vision and robotics, multi-keyed indexing for traditional databases, temporal
databases, ... | performance evaluation;analytical model;r-tree;buffer model;multidimensional indexing |
628045 | Dynamically Negotiated Resource Management for Data Intensive Application Suites. | AbstractIn contemporary computers and networks of computers, various application domains are making increasing demands on the system to move data from one place to another, particularly under some form of soft real-time constraint. A brute force technique for implementing applications in this type of domain demands exc... | Introduction
There is an emerging class of application programs, stimulated by the rapid evolution of computer
hardware and networks. These distributed applications are data intensive, requiring that diverse
data types (beyond the traditional numerical and character types) such as audio and video streams
be moved from ... | dynamic resource negotiation;multimedia support;execution levels;confidence-based scheduling;tailorable distributed object policies;soft real-time |
628048 | Natural Language Grammatical Inference with Recurrent Neural Networks. | AbstractThis paper examines the inductive inference of a complex grammar with neural networksspecifically, the task considered is that of training a network to classify natural language sentences as grammatical or ungrammatical, thereby exhibiting the same kind of discriminatory power provided by the Principles and Par... | Introduction
This paper considers the task of classifying natural language sentences as grammatical or ungrammatical.
We attempt to train neural networks, without the bifurcation into learned vs. innate components assumed by
Chomsky, to produce the same judgments as native speakers on sharply grammatical/ungrammatical ... | simulated annealing;grammatical inference;principles-and-parameters framework;recurrent neural networks;natural language processing;gradient descent;government-and-binding theory;automata extraction |
628059 | Justification for Inclusion Dependency Normal Form. | AbstractFunctional dependencies (FDs) and inclusion dependencies (INDs) are the most fundamental integrity constraints that arise in practice in relational databases. In this paper, we address the issue of normalization in the presence of FDs and INDs and, in particular, the semantic justification for Inclusion Depende... | Introduction
Functional dependencies (FDs) [Arm74, Mai83, Ull88, AA93] generalise the notions of entity integrity
and keys [Cod79] and inclusion dependencies (INDs) [Mit83, CFP84] generalise the notions
of referential integrity and foreign keys [Cod79, Dat86]. In this sense FDs and INDs are the most
fundamental data de... | relational database design;functional dependency;normal forms;inclusion dependency |
628066 | Scalable Algorithms for Association Mining. | AbstractAssociation rule discovery has emerged as an important problem in knowledge discovery and data mining. The association mining task consists of identifying the frequent itemsets and then, forming conditional implication rules among them. In this paper, we present efficient algorithms for the discovery of frequen... | Introduction
The association mining task is to discover a set of attributes shared among a large number of objects in
a given database. For example, consider the sales database of a bookstore, where the objects represent
customers and the attributes represent books. The discovered patterns are the set of books most fre... | data mining;equivalence classes;frequent itemsets;association rules;lattices;maximal cliques |
628075 | Constructing Bayesian Networks for Medical Diagnosis from Incomplete and Partially Correct Statistics. | AbstractThe paper discusses several knowledge engineering techniques for the construction of Bayesian networks for medical diagnostics when the available numerical probabilistic information is incomplete or partially correct. This situation occurs often when epidemiological studies publish only indirect statistics and ... | Introduction
Bayesian networks (BN) have emerged as some of the most successful tools for medical
diagnostics and many have been deployed in real medical environments or implemented
in off-the-shelf diagnostic software [Spi87, Sho93, WSB97]. Constructing
large BNs for such applications is in many ways similar to the kn... | medical diagnosis;bayesian networks;combining risk factors;leaky noisy-OR nodes |
628087 | An Approach to Active Spatial Data Mining Based on Statistical Information. | AbstractSpatial data mining presents new challenges due to the large size of spatial data, the complexity of spatial data types, and the special nature of spatial access methods.Most research in this area has focused on efficient query processing of static data. This paper introduces an active spatial data mining appro... | Introduction
Spatial data mining, i.e., discovery of interesting characteristics and patterns that may implicitly exist in spatial
databases, plays an important role in understanding spatial data and in capturing intrinsic relationships between spatial
and non-spatial data. Efficiency is a crucial challenge in spatial ... | active data mining;spatial databases;incremental trigger evaluation;spatial data mining |
628088 | A Database Approach for Modeling and Querying Video Data. | AbstractIndexing video data is essential for providing content-based access. In this paper, we consider how database technology can offer an integrated framework for modeling and querying video data. As many concerns in video (e.g., modeling and querying) are also found in databases, databases provide an interesting an... | Introduction
With recent progress in compression technology, it is
possible for computer to store huge amount of pictures, audio
and even video. If such media are widely used in today's
communication (e.g., in the form of home movies, education
and training, scholarly research, and corporate enterprise
solutions), effi... | rule-based query language;object-oriented modeling;content-based access of video;video indexing;video query;video database;video representation;constraint query language |
628095 | Enhancing Disjunctive Datalog by Constraints. | AbstractThis paper presents an extension of Disjunctive Datalog (${\rm{DATALOG}}^{\vee,}{^\neg}$) by integrity constraints. These are of two types: strong, that is, classical integrity constraints and weak, that is, constraints that are satisfied if possible. While strong constraints must be satisfied, weak constraints... | Introduction
Disjunctive Datalog (or DATALOG ;: ) programs [18, 15] are nowadays widely recognized as
a valuable tool for knowledge representation and commonsense reasoning [2, 34, 25, 20]. An
important merit of DATALOG ;: programs over normal (that is, disjunction-free) Datalog
programs is their capability to model in... | disjunctive datalog;deductive databases;knowledge representation;computational complexity;nonmonotonic reasoning |
628097 | Integrating Security and Real-Time Requirements Using Covert Channel Capacity. | AbstractDatabase systems for real-time applications must satisfy timing constraints associated with transactions in addition to maintaining data consistency. In addition to real-time requirements, security is usually required in many applications. Multilevel security requirements introduce a new dimension to transactio... | Introduction
Database security is concerned with the ability of a database management system to enforce a
security policy governing the disclosure, modification or destruction of information. Most secure
database systems use an access control mechanism based on the Bell-LaPadula model [3]. This
model is stated in terms... | concurrency control;database systems;real-time systems;covert channel analysis;multilevel security;locking protocols |
628100 | Exploiting Spatial Indexes for Semijoin-Based Join Processing in Distributed Spatial Databases. | AbstractIn a distributed spatial database system, a user may issue a query that relates two spatial relations not stored at the same site. Because of the sheer volume and complexity of spatial data, spatial joins between two spatial relations at different sites are expensive in terms of computation and transmission cos... | Introduction
Queries in spatial databases frequently involve relationships between two spatial entities. These
relationships include containment, intersection, adjacency and proximity. For example, the
query "which schools are adjacent to areas zoned for industrial purposes?" requires an adjacency
relationship, while t... | locational keys;spatial indexes;r-tree;spatial semijoin;distributed spatial database systems;query processing |
628111 | Finding Interesting Associations without Support Pruning. | AbstractAssociation-rule mining has heretofore relied on the condition of high support to do its work efficiently. In particular, the well-known a priori algorithm is only effective when the only rules of interest are relationships that occur very frequently. However, there are a number of applications, such as data mi... | Introduction
A prevalent problem in large-scale data mining is that of association-rule mining, first introduced
by Agrawal, Imielinski, and Swami [1]. This challenge is sometimes referred to as the market-basket
problem due to its origins in the study of consumer purchasing patterns in retail stores,
although the appl... | data mining;locality sensitive hashing;association rules;min hashing;similarity metric |
628118 | Simple Strategies to Encode Tree Automata in Sigmoid Recursive Neural Networks. | AbstractRecently, a number of authors have explored the use of recursive neural nets (RNN) for the adaptive processing of trees or tree-like structures. One of the most important language-theoretical formalizations of the processing of tree-structured data is that of deterministic finite-state tree automata (DFSTA). ma... | Introduction
During the last decade, a number of authors have explored the use of analog
recursive neural nets (RNN) for the adaptive processing of data laid out as
trees or tree-like structures such as directed acyclic graphs. In this arena,
Frasconi, Gori and Sperduti [5] have recently established a rather general
fo... | neural computation;recursive neural networks;analog neural networks;tree automata |
628121 | Generalization Ability of Folding Networks. | AbstractThe information theoretical learnability of folding networks, a very successful approach capable of dealing with tree structured inputs, is examined. We find bounds on the VC, pseudo-, and fat shattering dimension of folding networks with various activation functions. As a consequence, valid generalization of f... | Introduction
One particular problem of connectionistic methods dealing with structured objects is to find a
possibility which makes the processing of data with a priori unlimited size possible. Connectionistic
methods often use a distributed representation of the objects in a vector space of some fixed
dimension, where... | luckiness function;folding networks;VC dimension;UCED property;recurrent neural networks;computational learning theory |
628123 | Incremental Syntactic Parsing of Natural Language Corpora with Simple Synchrony Networks. | AbstractThis article explores the use of Simple Synchrony Networks (SSNs) for learning to parse English sentences drawn from a corpus of naturally occurring text. Parsing natural language sentences requires taking a sequence of words and outputting a hierarchical structure representing how those words fit together to f... | Introduction
This article explores the use of Simple Synchrony Networks (SSNs) for learning to parse English
sentences drawn from a corpus of naturally occurring text. The SSN has been defined
in previous work [17, 23], and is an extension of the Simple Recurrent Network (SRN) [6, 7].
The SSN extends SRNs with Temporal... | syntactic parsing;simple synchrony networks;natural language processing;temporal synchrony variable binding;connectionist networks |
628124 | Learning Distributed Representations of Concepts Using Linear Relational Embedding. | AbstractIn this paper, we introduce Linear Relational Embedding as a means of learning a distributed representation of concepts from data consisting of binary relations between these concepts. The key idea is to represent concepts as vectors, binary relations as matrices, and the operation of applying a relation to a c... | Introduction
Given data which consists of concepts and relations among concepts, our goal is to correctly predict unobserved
instances of relationships between concepts. We do this by representing each concept as a vector in
a Euclidean space and the relationships between concepts as linear operations.
To illustrate th... | learning structured data;concept learning;generalization on relational data;Linear Relational Embedding;feature learning;distributed representations |
628132 | Emergent Semantics through Interaction in Image Databases. | AbstractIn this paper, we briefly discuss some aspects of image semantics and the role that it plays for the design of image databases. We argue that images don't have an intrinsic meaning, but that they are endowed with a meaning by placing them in the context of other images and by the user interaction. From this obs... | where i are terminal symbols of the record definition language, Ri are non terminal symbols,
and j is the label of the production rule, then the meaning of R is:
The meaning of the whole record depends on the production rule and on the meaning of the
non terminals on the right side of the production, but not on the syn... | interactive databases;relevance feedback;man-machine interface;image databases;content-based image retrieval |
628133 | Data Semantics for Improving Retrieval Performance of Digital News Video Systems. | AbstractWe propose a novel four-step hybrid approach for retrieval and composition of video newscasts based on information contained in different metadata sets. In the first step, we use conventional retrieval techniques to isolate video segments from the data universe using segment metadata. In the second step, retrie... | Introduction
A challenging problem in video-based applications is achieving rapid search and retrieval of content
from a large corpus. Because of the computational cost of real-time image-based analysis for searching
such large data sets we pursue techniques based on off-line or semi-automated classification,
indexing,... | recall;news video composition;content metadata;structural metadata;precision;unstructured metadata;keyword vector;retrieval |
628140 | Global Scheduling for Flexible Transactions in Heterogeneous Distributed Database Systems. | AbstractA heterogeneous distributed database environment integrates a set of autonomous database systems to provide global database functions. A flexible transaction approach has been proposed for the heterogeneous distributed database environments. In such an environment, flexible transactions can increase the failure... | Introduction
A heterogeneous distributed database system (HDDBS) integrates a set of autonomous database
systems to provide global database functions. In a HDDBS environment, transaction management
is handled at both the global and local levels. As a confederation of pre-existing local
Current address: MCC, 3500 West B... | flexible transactions;concurrency control;heterogeneous and autonomous database;serializability;transaction management |
628151 | Segmented Information Dispersal (SID) Data Layouts for Digital Video Servers. | AbstractWe present a novel data organization for disk arraysSegmented Information Dispersal (SID). SID provides protection against disk failures while ensuring that the reconstruction of the missing data requires only relatively small contiguous accesses to the available disks. SID has a number of properties that make ... | Introduction
Digital video server systems must provide timely delivery of video stream data to an ensemble of users even in
degraded modes in which one or more system disks are not operational. One design problem is the following:
for a given set of disks, which video data layout can provide this service while avoiding... | disk arrays;algorithms;video servers;data structures;declustering;separated difference sets |
628163 | Minimizing Bandwidth Requirements for On-Demand Data Delivery. | AbstractTwo recent techniques for multicast or broadcast delivery of streaming media can provide immediate service to each client request, yet achieve considerable client stream sharing which leads to significant server and network bandwidth savings. This paper considers 1) how well these recently proposed techniques p... | Introduction
This paper considers the server (disk I/O and network I/O) bandwidth required for on-demand real-time
delivery of large data files, such as audio and video files 1 . Delivery of the data might be done via the Internet or
via a broadband (e.g., satellite or cable) network, or some combination of these netwo... | video-on-demand;streaming media;scalable protocols;performance evaluation;multicast |
628166 | Nondeterministic, Nonmonotonic Logic Databases. | AbstractWe consider in this paper an extension of Datalog with mechanisms for temporal, nonmonotonic, and nondeterministic reasoning, which we refer to as Datalog++. We show, by means of examples, its flexibility in expressing queries concerning aggregates and data cube. Also, we show how iterated fixpoint and stable m... | Introduction
Motivations. The name Datalog++ is used in this paper to refer to Datalog
extended with mechanisms supporting:
- a limited form of temporal reasoning, by means of temporal, or stage, arguments
of relations, ranging over a discrete temporal domain, in the style
of [5];
- nonmonotonic reasoning, by means of ... | stable models;negation;nondeterminism;logic programming;databases |
628189 | Mining Optimized Association Rules with Categorical and Numeric Attributes. | AbstractMining association rules on large data sets has received considerable attention in recent years. Association rules are useful for determining correlations between attributes of a relation and have applications in marketing, financial, and retail sectors. Furthermore, optimized association rules are an effective... | Introduction
Association rules, introduced in [1], provide a useful
mechanism for discovering correlations among the underlying
data. In its most general form, an association
rule can be viewed as being defined over attributes of
a relation, and has the form C
are conjunctions of conditions, and each condition
is eithe... | algorithm;knowledge discovery;data mining;optimized association rules |
628191 | Finding Localized Associations in Market Basket Data. | AbstractIn this paper, we discuss a technique for discovering localized associations in segments of the data using clustering. Often, the aggregate behavior of a data set may be very different from localized segments. In such cases, it is desirable to design algorithms which are effective in discovering localized assoc... | Introduction
Market basket data consists of sets of items bought together by customers. One such set of
items is called a transaction. In recent years, a considerable amount of work has been done
in trying to find associations among items in large groups of transactions [3, 4]. Considerable
amount of work has also been... | market basket data;clustering;association rules |
628197 | A Comprehensive Analytical Performance Model for Disk Devices under Random Workloads. | AbstractOur goal with this paper is to contribute a common theoretical framework for studying the performance of disk-storage devices. Understanding the performance behavior of these devices will allow prediction of the I/O cost in modern applications. Current disk technologies differ in terms of the fundamental modeli... | Introduction
The performance modeling of direct-access storage devices is concerned with expressing mathematically
the technology behind them and the way their components cooperate in order to perform
a task and is used to predict the performance of those devices. Such a modeling can be useful in
estimating the expecte... | performance modeling and prediction;disk technologies;zoned disks |
628198 | High-Dimensional Similarity Joins. | AbstractMany emerging data mining applications require a similarity join between points in a high-dimensional domain. We present a new algorithm that utilizes a new index structure, called the $\epsilon$ tree, for fast spatial similarity joins on high-dimensional points. This index structure reduces the number of neigh... | Introduction
Many emerging data mining applications require efficient
processing of similarity joins on high-dimensional
points. Examples include applications in time-series
databases[1, 2], multimedia databases [9, 14, 13], medical
databases [3, 21], and scientific databases[22]. Some typical
queries in these applicat... | similar time sequences;data mining;similarity join |
628213 | Production Systems with Negation as Failure. | We study action rule-based systems with two forms of negation, namely classical negation and negation as failure to find a course of actions. We show by several examples that adding negation as failure to such systems increases their expressiveness in the sense that real life problems can be represented in a natural an... | This is a sound and complete implementation, though computationally
hard as shown in the paper.
Keywords: rule-based systems, knowledge-based systems, rule-based process-
ing, expert systems, knowledge representation
Note: This paper is a revised and extended version of [9].
1 Introduction and Motivations
In this secti... | rule-based processing;knowledge-based systems;rule-based systems;expert systems;knowledge representation |
628215 | A Comparative Study of Various Nested Normal Forms. | As object-relational databases (ORDBs) become popular in the industry, it is important for database designers to produce database schemes with good properties in these new kinds of databases. One distinguishing feature of an ORDB is that its tables may not be in first normal form. Hence, ORDBs may contain nested relati... | Introduction
Object-Relational Databases (ORDBs) could be an alternative for the next-generation databases [SBM98].
This hybrid approach is sound because it is based on mature relational technology. By adding object-oriented
features to a relational database, an ORDB is obtained. Since this approach seems like a natura... | data redundancy;nested normal forms;nested databases;acyclic database schemes;design flexibility;algorithms;object-relational database management systems;object-relational databases;nested database design;nested database schemes;nested relations;conflict-free sets of MVDs;nested relation schemes;SQL:1999 |
628217 | A Performance Study of Robust Load Sharing Strategies for Distributed Heterogeneous Web Server Systems. | Replication of information across multiple servers is becoming a common approach to support popular Web sites. A distributed architecture with some mechanisms to assign client requests to Web servers is more scalable than any centralized or mirrored architecture. In this paper, we consider distributed systems in which ... | Introduction
With ever increasing tra-c demand on popular Web sites, a parallel or distributed architecture
can provide transparent access to the users to preserve one logical interface, such
as www.site.org. System scalability and transparency require some internal mechanism
that automatically assigns client requests ... | performance analysis;load balancing;distributed systems;domain name system;World Wide Web;global scheduling algorithms |
628247 | Clustering for Approximate Similarity Search in High-Dimensional Spaces. | In this paper, we present a clustering and indexing paradigm (called Clindex) for high-dimensional search spaces. The scheme is designed for approximate similarity searches, where one would like to find many of the data points near a target point, but where one can tolerate missing a few near points. For such searches,... | Introduction
Similarity search has generated a great deal of interest lately because of
applications such as similar text/image search and document/image copy
detection. These applications characterize objects (e.g., images and text
documents) as feature vectors in very high-dimensional spaces [13, 23]. A
user submits ... | approximate search;high-dimensional index;clustering;similarity search |
628254 | Hashing Methods for Temporal Data. | External dynamic hashing has been used in traditional database systems as a fast method for answering membership queries. Given a dynamic set S of objects, a membership query asks whether an object with identity k is in (the most current state of) S. This paper addresses the more general problem of Temporal Hashing. In... | Introduction
Hashing has been used as a fast method to address membership queries. Given a set S of objects
distinguished by some identity attribute (oid), a membership query asks whether object with oid k
is in set S. Hashing can be applied either as a main memory scheme (all data fits in main-memory
[DKM+88, FNSS92])... | hashing;transaction time;access methods;data structures;temporal databases |
628284 | Efficient Queries over Web Views. | AbstractLarge Web sites are becoming repositories of structured information that can benefit from being viewed and queried as relational databases. However, querying these views efficiently requires new techniques. Data usually resides at a remote site and is organized as a set of related HTML documents, with network a... | Introduction
As the Web becomes a preferred medium for disseminating information of all
kinds, the sets of pages at many Web sites have come to exhibit regular and
complex structure not unlike the structures that are described by schemes in
database systems. For example, Atzeni et al. [4] show how to describe the struc... | query optimization;query languages;view maintenance |
628293 | A Statistical Method for Estimating the Usefulness of Text Databases. | AbstractSearching desired data on the Internet is one of the most common ways the Internet is used. No single search engine is capable of searching all data on the Internet. The approach that provides an interface for invoking multiple search engines for each user query has the potential to satisfy more users. When the... | Introduction
The Internet has become a vast information source in recent years. To help ordinary users find desired data in
the Internet, many search engines have been created. Each search engine has a corresponding database that
defines the set of documents that can be searched by the search engine. Usually, an index ... | metasearch;information resource discovery;information retrieval |
628383 | Rigid Body Segmentation and Shape Description from Dense Optical Flow Under Weak Perspective. | AbstractWe present an algorithm for identifying and tracking independently moving rigid objects from optical flow. Some previous attempts at segmentation via optical flow have focused on finding discontinuities in the flow field. While discontinuities do indicate a change in scene depth, they do not in general signal a... | Introduction
Visual motion can provide us with two vital pieces of information: the segmentation of the
visual scene into distinct moving objects and shape information about those objects. In this
paper we will examine how the use of epipolar geometry under the assumption of rigidly moving
objects can be used to provid... | shape from motion;fundamental matrix;epipolar constraint;scene partitioning problem;motion segmentation;optical flow |
628464 | On the Advantages of Polar and Log-Polar Mapping for Direct Estimation of Time-To-Impact from Optical Flow. | The application of an anthropomorphic retina-like visual sensor and the advantages of polar and log-polar mapping for visual navigation are investigated. It is demonstrated that the motion equations that relate the egomotion and/or the motion of the objects in the scene to the optical flow are considerably simplified i... | Introduction
Autonomous systems should be able to control their movements in the environment
and adapt to unexpected events. This is possible only if the robot
has the capability to "sense" the environment. Among the sensors used for
robots, visual sensors are the ones that require the greatest computational
power to p... | direct estimation;log-polar mapping;motion estimation;egomotion;tracking;visual navigation;anthropomorphic retina-like visual sensor;CCD image sensors;time-to-impact;optical flow |
628513 | Comparing Images Using the Hausdorff Distance. | The Hausdorff distance measures the extent to which each point of a model set lies near some point of an image set and vice versa. Thus, this distance can be used to determine the degree of resemblance between two objects that are superimposed on one another. Efficient algorithms for computing the Hausdorff distance be... | Introduction
A central problem in pattern recognition and computer vision is determining the extent
to which one shape differs from another. Pattern recognition operations such as correlation
and template matching (cf. [17]) and model-based vision methods (cf. [4, 8, 11])
can all be viewed as techniques for determining... | shape comparison methods;image comparison;image processing;binary image;translation;position error tolerance;hausdorff distance;rigid motion |
628552 | Stability of Phase Information. | This paper concerns the robustness of local phase information for measuring image velocity and binocular disparity. It addresses the dependence of phase behavior on the initial filters as well as the image variations that exist between different views of a 3D scene. We are particularly interested in the stability of ph... | Introduction
An important class of image matching techniques has emerged based on phase information; that is,
the phase behaviour in band-pass filtered versions of different views of a 3-d scene [3, 7, 8, 11, 13, 15,
17, 18, 25, 27, 30, 32, 33]. These include phase-difference and phase-correlation techniques for discre... | local phase information;geometric deformations;frequency bandwidths;initial filters;image processing;robustness;image recognition;binocular disparity;filtering and prediction theory;3D scene;image velocity;zero-crossing tracking;spatial position;phase singularities;frequency stability;phase stability;optical flow |
628676 | Cooperative Robust Estimation Using Layers of Support. | AbstractWe present an approach to the problem of representing images that contain multiple objects or surfaces. Rather than use an edge-based approach to represent the segmentation of a scene, we propose a multilayer estimation framework which uses support maps to represent the segmentation of the image into homogeneou... | Introduction
Real-world perceptual systems must deal with complicated and cluttered environments. To
succeed in such environments, a system must be able to recover salient parameters that are
relevant for the task at hand. However many of the techniques developed to estimate these
parameters are designed for homogeneou... | transparency;robust estimation;structure from motion;range segmentation;segmentation;perceptual organization;multiple models;motion segmentation |
628679 | Linear and Incremental Acquisition of Invariant Shape Models From Image Sequences. | AbstractWe show how to automatically acquire Euclidian shape representations of objects from noisy image sequences under weak perspective. The proposed method is linear and incremental, requiring no more than pseudoinverse. A nonlinear, but numerically sound preprocessing stage is added to improve the accuracy of the r... | Introduction
In model-based recognition, images are matched against stored libraries of three-dimensional object
representations, so that a good match implies recognition of the object. The recognition process
is greatly simplified if the quality of the match can be determined without camera calibration,
namely, withou... | structure from motion;linear reconstruction;weak perspective;gramian;factorization method;affine coordinates;affine shape;euclidean shape |
628687 | Modal Matching for Correspondence and Recognition. | AbstractModal matching is a new method for establishing correspondences and computing canonical descriptions. The method is based on the idea of describing objects in terms of generalized symmetries, as defined by each objects eigenmodes. The resulting modal description is used for object recognition and categorization... | Introduction
A key problem in machine vision is how to describe fea-
tures, contours, surfaces, and volumes so that they can
be recognized and matched from view to view. The primary
difficulties are that object descriptions are sensitive
to noise, that an object can be nonrigid, and that an ob-
ject's appearance deform... | object recognition;vibration modes;finite element methods;correspondence;modal analysis;deformation;shape invariants;eigenmodes;shape description |
628688 | On Discontinuity-Adaptive Smoothness Priors in Computer Vision. | AbstractA variety of analytic and probabilistic models in connection to Markov random fields (MRFs) have been proposed in the last decade for solving low level vision problems involving discontinuities. This paper presents a systematic study of these models and defines a general discontinuity adaptive (DA) MRF model. B... | Introduction
MOOTHNESS is a generic assumption underlying a
wide range of physical phenomena. It characterizes the
coherence and homogeneity of matter within a scope of
space (or an interval of time). It is one of the most common
assumptions in computer vision models, in particular,
those formulated in terms of Markov ... | energy functions;regularization;markov random fields;computer vision;minimization;euler equation;discontinuities |
628710 | Algebraic Functions For Recognition. | AbstractIn the general case, a trilinear relationship between three perspective views is shown to exist. The trilinearity result is shown to be of much practical use in visual recognition by alignmentyielding a direct reprojection method that cuts through the computations of camera transformation, scene structure and e... | Introduction
We establish a general result about algebraic connections
across three perspective views of a 3D scene and demonstrate
its application to visual recognition via alignment.
We show that, in general, any three perspective views of a
scene satisfy a pair of trilinear functions of image coordi-
nates. In the l... | visual recognition;algebraic and geometric invariants;reprojection;projective geometry;alignment |
628731 | Person Identification Using Multiple Cues. | AbstractThis paper presents a person identification system based on acoustic and visual features. The system is organized as a set of non-homogeneous classifiers whose outputs are integrated after a normalization step. In particular, two classifiers based on acoustic features and three based on visual ones provide data... | Introduction
The identification of a person interacting with
computers represents an important task for automatic
systems in the area of information retrieval,
automatic banking, control of access to security ar-
eas, buildings and so on. The need for a reliable
identification of interacting users is obvious. At the
sa... | classification;learning;face recognition;correlation;template matching;robust statistics;speaker recognition |
628733 | Logical/Linear Operators for Image Curves. | AbstractWe propose a language for designing image measurement operators suitable for early vision. We refer to them as logical/linear (L/L) operators, since they unify aspects of linear operator theory and Boolean logic. A family of these operators appropriate for measuring the low-order differential structure of image... | Introduction
There is no shortage of so-called "edge-detectors" and "line-detectors" in computer
vision. These are operators intended to respond to lines and edges in images. Many
different designs have been proposed, based on a range of optimality criteria (e.g
[1, 2]), and many of these designs exhibit properties in ... | nonlinear operators;edge detection;image processing;feature extraction;computer vision |
628753 | Symmetry as a Continuous Feature. | AbstractSymmetry is treated as a continuous feature and a Continuous Measure of Distance from Symmetry in shapes is defined. The Symmetry Distance (SD) of a shape is defined to be the minimum mean squared distance required to move points of the original shape in order to obtain a symmetrical shape. This general definit... | Introduction
One of the basic features of shapes and objects is symme-
try. Symmetry is considered a pre-attentive feature which
enhances recognition and reconstruction of shapes and objects
[4]. Symmetry is also an important parameter in physical
and chemical processes and is an important criterion
in medical diagnosi... | local symmetry;fuzzy shapes;face orientation;occlusion;similarity measure;symmetry distance;symmetry |
628768 | Thermophysical Algebraic Invariants from Infrared Imagery for Object Recognition. | AbstractAn important issue in developing a model-based vision system is the specification of features that are invariant to viewing and scene conditions and also specific, i.e., the feature must have different values for different classes of objects. We formulate a new approach for establishing invariant features. Our ... | Introduction
Non-visible modalities of sensing have been shown to greatly increase the amount of information
that can be used for object recognition. A very popular and increasingly affordable sensor
modality is thermal imaging - where non-visible radiation is sensed in the long-wave infrared
(LWIR) spectrum of 8-m to ... | image understanding;thermal image;invariance;physics-based computer vision;model-based vision |
628779 | The Complex Representation of Algebraic Curves and Its Simple Exploitation for Pose Estimation and Invariant Recognition. | AbstractNew representations are introduced for handling 2D algebraic curves (implicit polynomial curves) of arbitrary degree in the scope of computer vision applications. These representations permit fast, accurate pose-independent shape recognition under Euclidean transformations with a complete set of invariants, and... | Introduction
For shape recognition involving large databases, position-invariant 2D shape-recognition and
pose-estimation have to be performed by fast algorithms providing robust accurate estimates
subject to noise, missing data (perhaps due to partial occlusion) and local deformations. There
is a sizeable literature o... | implicit polynomial curves;algebraic curves;shape recognition;complete-sets of rotation invariants;complex polynomials;euclidean invariants;pose estimation;shape representation;curve centers;pose-independent curve recognition |
628780 | A Cooperative Algorithm for Stereo Matching and Occlusion Detection. | AbstractThis paper presents a stereo algorithm for obtaining disparity maps with occlusion explicitly detected. To produce smooth and detailed disparity maps, two assumptions that were originally proposed by Marr and Poggio are adopted: uniqueness and continuity. That is, the disparity maps have a unique value per pixe... | Introduction
Stereo vision can produce a dense disparity map. The resultant disparity map
should be smooth and detailed; continuous and even surfaces should produce a region of
smooth disparity values with their boundary precisely delineated, while small surface
elements should be detected as separately distinguishable... | stereo vision;3D vision;occlusion detection |
628789 | Combining Belief Networks and Neural Networks for Scene Segmentation. | We are concerned with the problem of image segmentation, in which each pixel is assigned to one of a predefined finite number of labels. In Bayesian image analysis, this requires fusing together local predictions for the class labels with a prior model of label images. Following the work of, we consider the use of tree... | Introduction
We are concerned with the problem of image segmentation in which each pixel will be assigned to one out of
a nite number of classes. Our work is applied to images of outdoor scenes, with class labels such as \sky",
\road", \vegetation", etc. Such scenes are typically complex, involving many dierent objects... | neural network;scaled-likelihood method;conditional maximum-likelihood training;gaussian mixture model;expectation-maximization EM;Markov random field MRF;tree-structured belief network TSBN;hierarchical modeling |
628814 | Information-Theoretic Bounds on Target Recognition Performance Based on Degraded Image Data. | AbstractThis paper derives bounds on the performance of statistical object recognition systems, wherein an image of a target is observed by a remote sensor. Detection and recognition problems are modeled as composite hypothesis testing problems involving nuisance parameters. We develop information-theoretic performance... | Introduction
Typical target recognition problems involve detection and classification of targets as well as
estimation of target parameters such as location and orientation. A set of possible targets
comprises objects such as tanks, trucks, and planes. The scene in which targets are present is
acquired by sensors such ... | object recognition;multisensor data fusion;imaging sensors;performance metrics;data compression;automatic target recognition |
628823 | A Maximum Variance Cluster Algorithm. | AbstractWe present a partitional cluster algorithm that minimizes the sum-of-squared-error criterion while imposing a hard constraint on the cluster variance. Conceptually, hypothesized clusters act in parallel and cooperate with their neighboring clusters in order to minimize the criterion and to satisfy the variance ... | Introduction
Data clustering is an extensively investigated problem for which many algorithms have been reported
[18], [26]. Roughly, cluster algorithms can be categorized in hierarchical and partitional algorithms.
Hierarchical algorithms deliver a hierarchy of possible clusterings, while partitional cluster algorithm... | partitional clustering;cluster validity;cluster analysis;cluster tendency assessment |
628848 | Direct Recovery of Planar-Parallax from Multiple Frames. | AbstractIn this paper, we present an algorithm that estimates dense planar-parallax motion from multiple uncalibrated views of a 3D scene. This generalizes the "plane+parallax" recovery methods to more than two frames. The parallax motion of pixels across multiple frames (relative to a planar surface) is related to the... | Introduction
The recovery of the 3D structure of a scene and the camera epipolar-geometries
(or camera motion) from multiple views has been a topic of considerable research.
The large majority of the work on structure-from-motion (SFM) has assumed
that correspondences between image features (typically a sparse set of i... | structure from motion;multiframe analysis;direct gradient-based methods;correspondence estimation;plane+parallax |
628884 | Lambertian Reflectance and Linear Subspaces. | AbstractWe prove that the set of all Lambertian reflectance functions (the mapping from surface normals to intensities) obtained with arbitrary distant light sources lies close to a 9D linear subspace. This implies that, in general, the set of images of a convex Lambertian object obtained under a wide variety of lighti... | Introduction
One of the most basic problems in vision is to understand how variability in lighting affects the images
that an object can produce. Even when lights are isotropic and distant, smooth Lambertian objects can
produce infinite-dimensional sets of images (Belhumeur and Kriegman [1]). But recent experimental
wo... | object recognition;linear subspaces;face recognition;specular;illumination;spherical harmonics;lambertian |
628975 | An Efficient Data Dependence Analysis for Parallelizing Compilers. | A novel algorithm, called the lambda test, is presented for an efficient and accurate data dependence analysis of multidimensional array references. It extends the numerical methods to allow all dimensions of array references to be tested simultaneously. Hence, it combines the efficiency and the accuracy of both approa... | Introduction
A parallelizing compiler relies on data dependence analysis to detect
independent operations in a user's program. For array operands, the analysis needs to
check the existence of integer solutions to a linear system obtained from array
subscript expressions. In simple cases, this can be done rather easily.... | numerical methods;hyperplanes;parafrase;array subscripts;fortran program parallelization restructurer;linear inequalities;parallelizing compilers;lambda test;multidimensional array references;FORTRAN;index termsprogram restructuring;data dependence analysis;loop bounds;parallel programming;program compilers;convex set |
629004 | An Empirical Study of Fortran Programs for Parallelizing Compilers. | Some results are reported from an empirical study of program characteristics, that are important in parallelizing compiler writers, especially in the area of data dependence analysis and program transformations. The state of the art in data dependence analysis and some parallel execution techniques are examined. The ma... | Introduction
The key to the success of a parallelizing compiler is to have accurate data depen
ence information on all of the statements in a program. We would like to identify all
of the independent variable references and statements in a program, so they can be
xecuted independently (i.e. in parallel). Several algori... | integer-valued test;parallelizing compilers;fortran programs;FORTRAN;program transformations;program characteristics;data dependence analysis;program compilers;index termsarray references |
629046 | Interactive Parallel Programming using the ParaScope Editor. | The ParaScope Editor, an intelligent interactive editor for parallel Fortran programs, which is the centerpiece of the ParaScope project, an integrated collection of tools to help scientific programmers implement correct and efficient parallel programs, is discussed. ParaScope Editor reveals to users potential hazards ... | Introduction
The widespread availability of affordable parallel machines has increasingly challenged the
abilities of programmers and compiler writers alike. Programmers, eager to use new machines
to speed up existing sequential scientific codes, want maximal performance with minimal ef-
fort. The success of automatic ... | scientific programmers;efficient parallel programs;general user editing;hybrid text;modified program;integrated collection;parascopeproject;exploratory programming style;text editing;FORTRAN;powerful interactive program transformations;interactive programming;Index TermsParaScope Editor;structureediting facility;intell... |
629048 | An Implementation of Interprocedural Bounded Regular Section Analysis. | Regular section analysis, which summarizes interprocedural side effects on subarrays in a form useful to dependence analysis, while avoiding the complexity of prior solutions, is shown to be a practical addition to a production compiler. Optimizing compilers should produce efficient code even in the presence of high-le... | Introduction
A major goal of compiler optimization research is to generate code that is efficient enough to
encourage the use of high-level language constructs. In other words, good programming practice
This research has been supported by the National Science Foundation under grant CCR 88-09615, by the IBM
Corporation,... | programmingsupport systems;linear algebra subroutines;program testing;index termsoptimizing compilers;procedure calls;application codes;high-level language constructs;subarrays;interprocedural bounded regular section analysis;production compiler;RiceCompiler Evaluation Program Suite;dependence analysis;RiCEPS;scientifi... |
629058 | Compile-Time Techniques for Data Distribution in Distributed Memory Machines. | A solution to the problem of partitioning data for distributed memory machines is discussed. The solution uses a matrix notation to describe array accesses in fully parallel loops, which allows the derivation of sufficient conditions for communication-free partitioning (decomposition) of arrays. A series of examples th... | Introduction
In distributed memory machines such as the Intel iPSC/2 and NCUBE, each process has its own
address space and processes must communicate explicitly by sending and receiving messages. Local
memory accesses on these machines are much faster than those involving inter-processor commu-
nication. As a result, t... | matrix algebra;matrixnotation;data decompositions;parallel loops;communication-freepartitioning;data distribution;linear references;index termscompile time;program compilers;parallel programming;heuristics;sufficient conditions;array accesses;data partitioning;distributed memory machines;loop transformations |
629077 | Demonstration of Automatic Data Partitioning Techniques for Parallelizing Compilers on Multicomputers. | An approach to the problem of automatic data partitioning is introduced. The notion of constraints on data distribution is presented, and it is shown how, based on performance considerations, a compiler identifies constraints to be imposed on the distribution of various data structures. These constraints are then combi... | Introduction
Distributed memory multiprocessors (multicomputers) are increasingly being used for providing high levels
of performance for scientific applications. The distributed memory machines offer significant advantages
over their shared memory counterparts in terms of cost and scalability, but it is a widely accep... | constraints;datadistribution;perfectbenchmarks;linpack;parallelizing compilers;fortran programs;data structures;index termsautomatic data partitioning;scientific application programs;multicomputers;eispack libraries;parallel programming;program compilers |
629113 | Coterie Join Algorithm. | Given a set of nodes in a distributed system, a coterie is a collection of subsets of the set of nodes such that any two subsets have a non empty intersection and are not properly contained in one another. A subset of nodes in a coterie is called a quorum. An algorithm, called the join algorithm, which takes nonempty c... | Introduction
In computer systems, the problem of mutual exclusion is an important issue. In
a distributed environment, mutual exclusion protocols should gracefully tolerate
node and communication line failures. One such class of protocols may be constructed
based on coteries [6]. Given a set of nodes U in the system, a... | nonempty intersection;trees mathematics;index termsdistributed system;treecoteries;composite coterie;join algorithm;distributedalgorithms;read and write quorums;nonempty coteries;replica control protocol |
629124 | Evaluation of NUMA Memory Management Through Modeling and Measurements. | Dynamic page placement policies for NUMA (nonuniform memory access time)shared-memory architectures are explored using two approaches that complement eachother in important ways. The authors measure the performance of parallel programsrunning on the experimental DUnX operating system kernel for the BBN GP1000, whichsup... | Introduction
NUMA (nonuniform memory access time) multiprocessor designs are of increasing importance
because they support shared memory on a large scale. For such systems, the placement and
movement of code and data are crucial to performance. This need to deal with data placement
issues has been called the "NUMA Prob... | local/remote NUMA architecture;experimental DUnX operating system kernel;memorysystem performance;storage allocation;remotely referenced;Index TermsNUMA memory management;experimental data;parallel programs;BBNGP1000;approximate mean-value analysistechniques;dynamic multiple-copy pageplacement;model predictions;highly ... |
629154 | An Efficient Heuristic for Permutation Packet Routing on Meshes with Low Buffer Requirements. | Even though exact algorithms exist for permutation routine of n/sup 2/ messages on an*n mesh of processors which require constant size queues, the constants are very largeand the algorithms very complicated to implement. A novel, simple heuristic for the above problem is presented. It uses constant and very small size ... | Introduction
An important task in the design of parallel computers is the development of efficient parallel
data transfer algorithms [1] [9]. The two fundamental performance measurements here are, the
number of parallel steps required to complete the message (packet) transfer and the additional
buffer (queue) size need... | parallel architectures;parallel algorithms;upper bound;index termsheuristic;transposition;permutation packet routing;low buffer requirements;exact algorithms;meshes;packet switching;optimal time inversion |
629166 | On the Efficiency of Parallel Backtracking. | Analytical models and experimental results concerning the average case behavior ofparallel backtracking are presented. Two types of backtrack search algorithms areconsidered: simple backtracking, which does not use heuristics to order and prunesearch, and heuristic backtracking, which does. Analytical models are used t... | Introduction
Consider the problem of finding a solution in a state-space tree containing one or more
solutions[10, 28, 26, 6]. Backtracking, also called Depth-first Search, is a widely used technique
for solving such problems because of its storage efficiency [13, 28]. Throughout the
paper, we use the two names interch... | parallel algorithms;index termsparallel backtracking;speedup;heuristicbacktracking;search problems;backtrack search algorithms;simple backtracking |
629185 | A Unified Formalization of Four Shared-Memory Models. | The authors present a data-race-free-1, shared-memory model that unifies four earliermodels: weak ordering, release consistency (with sequentially consistent specialoperations), the VAX memory model, and data-race-free-0. Data-race-free-1 unifies themodels of weak ordering, release consistency, the VAX, and data-race-f... | Introduction
A memory model for a shared-memory multiprocessor system is a formal specification of how memory
operations in a program will appear to execute to the programmer. In particular, a memory model specifies the
values that may be returned by read operations executed on a shared-memory system. This paper presen... | hazards and raceconditions;data-race-free-1;shared-memory models;weak ordering;shared memory systems;formalization;index termsmultiprocessors;data-race-free-0;sequential consistency;release consistency |
629269 | Detection of Weak Unstable Predicates in Distributed Programs. | This paper discusses detection of global predicates in a distributed program. Earlieralgorithms for detection of global predicates proposed by Chandy and Lamport (1985)work only for stable predicates. A predicate is stable if it does not turn false once itbecomes true. Our algorithms detect even unstable predicates, wi... | Introduction
A distributed program is one that runs on multiple processors
connected by a communication network. The state
of such a program is distributed across the network and
no process has access to the global state at any instant.
Detection of a global predicate, i.e. a condition that depends
on the state of mult... | weak unstable predicates;distributed memory systems;distributed programs;programtesting;global predicates;sun workstations;testing;UNIX;program debugging;debugging;distributed algorithms;distributed debugger;weakconjunctive predicates;message complexity;index termscommunication complexity |
629280 | Structuring Fault-Tolerant Object Systems for Modularity in a Distributed Environment. | The object-oriented approach to system structuring has found widespread acceptanceamong designers and developers of robust computing systems. The authors propose asystem structure for distributed programming systems that support persistent objects anddescribe how properties such as persistence and recoverability can be... | Introduction
One computational model that has been advocated for constructing robust
distributed applications is based upon the concept of using nested atomic
actions (nested atomic transactions) controlling operations on persistent
(long-lived) objects. In this model, each object is an instance of some class.
The clas... | modularity;distributed computing;atomic actions;fault-tolerantobject systems;index termsobject-oriented methods;object-oriented systems;persistent objects;atomic transactions;distributed programming systems;migration;replication;distributed processing;object-oriented approach;distributed systems;fault tolerance;distrib... |
629283 | Optimal Processor Assignment for a Class of Pipelined Computations. | The availability of large-scale multitasked parallel architectures introduces the followingprocessor assignment problem. We are given a long sequence of data sets, each of whichis to undergo processing by a collection of tasks whose intertask data dependencies forma series-parallel partial order. Each individual task i... | Introduction
In recent years much research has been devoted to the problem of mapping large computations onto
a system of parallel processors. Various aspects of the general problem have been studied, including
different parallel architectures, task structures, communication issues and load balancing [8, 13].
Typically... | data sets;parallel architectures;series-parallel partial order;series-parallel task system;data dependencies;index termspipeline processing;series analysis;pipelined computations;task structure;multitasked parallel architectures;computer vision;parallel analysis;resource allocation;processor assignment problem |
629334 | On the Performance of Synchronized Programs in Distributed Networks with Random Processing Times and Transmission Delays. | A synchronizer is a compiler that transforms a program designed to run in a synchronousnetwork into a program that runs in an asynchronous network. The behavior of a simplesynchronizer, which also represents a basic mechanism for distributed computing and forthe analysis of marked graphs, was studied by S. Even and S. ... | INTRODUCTION
Consider a network of processors which communicate by sending messages along communication
links. The network is synchronous if there is a global clock whose beats are heard by
all the processors simultaneously, and the time interval between clock beats is long enough
for all messages to reach their destin... | message passing;distributed computing;exponential distribution;synchronisation;graph theory;probabilitydistributions;parallel programming;marked graphs;compiler;asynchronous network;transmission delays;bottleneck processor;index termsprogram compilers;processing times;performance measure;synchronized programs;distribut... |
629351 | Asynchronous Problems on SIMD Parallel Computers. | AbstractOne of the essential problems in parallel computing is: Can SIMD machines handle asynchronous problems? This is a difficult, unsolved problem because of the mismatch between asynchronous problems and SIMD architectures. We propose a solution to let SIMD machines handle general asynchronous problems. Our approac... | Introduction
1.1. Can SIMD Machines Handle Asynchronous Problems?
The current parallel supercomputers have been developed as two major architectures: the
SIMD (Single Instruction Multiple Data) architecture and the MIMD (Multiple Instruction Multiple
architecture. The SIMD architecture consists of a central control uni... | thread model;scalability;irregular and dynamic applications;load balancing;portable programming environment;SIMD parallel computers |
629361 | Executing Algorithms with Hypercube Topology on Torus Multicomputers. | AbstractMany parallel algorithms use hypercubes as the communication topology among their processes. When such algorithms are executed on hypercube multicomputers the communication cost is kept minimum since processes can be allocated to processors in such a way that only communication between neighbor processors is re... | Introduction
A hypercube communication topology is frequently found in real parallel applications. Some
examples include parallel algorithms for FFT, sorts, etc. [3], [11]. These algorithms will be called
hypercube algorithms or d-cube algorithms, where d is the number of dimensions of the
hypercube. A hypercube algori... | graph embeddings;torus multicomputers;hypercubes;mapping of parallel algorithms;scalable distributed memory multiprocessors |
629396 | Performance Considerations of Shared Virtual Memory Machines. | AbstractGeneralized speedup is defined as parallel speed over sequential speed. In this paper the generalized speedup and its relation with other existing performance metrics, such as traditional speedup, efficiency, scalability, etc., are carefully studied. In terms of the introduced asymptotic speed, we show that the... | Introduction
In recent years parallel processing has enjoyed unprecedented attention from researchers, government
agencies, and industries. This attention is mainly due to the fact that, with the current circuit
technology, parallel processing seems to be the only remaining way to achieve higher performance.
However, w... | shared virtual memory;speedup;scalability;performance evaluation;performance metrics;high performance computing;parallel processing |
629399 | Square Meshes Are Not Optimal for Convex Hull Computation. | AbstractRecently it has been noticed that for semigroup computations and for selection rectangular meshes with multiple broadcasting yield faster algorithms than their square counterparts. The contribution of this paper is to provide yet another example of a fundamental problem for which this phenomenon occurs. Specifi... | Introduction
One of the fundamental heuristics in pattern recognition, image processing, and robot navigation,
involves approximating real-world objects by convex sets. For obvious reasons, one is typically
interested in the convex hull of a set S of points, defined as the smallest convex set that contains S
[39, 40]. ... | parallel algorithms;image processing;computational geometry;convex hulls;pattern recognition;meshes with broadcasting |
629409 | Globally Consistent Event Ordering in One-Directional Distributed Environments. | AbstractWe consider communication structures for event ordering algorithms in distributed environments where information flows only in one direction. Example applications are multilevel security and hierarchically decomposed databases. Although the most general one-directional communication structure is a partial order... | Introduction
We consider the ordering of events in a distributed environment. For our
purposes, a distributed environment is one where a set of events compose
some computation, the events occur at a network of sites, and sites communicate
by passing messages. Some applications impose restrictions on the
communication s... | distributed networks;partial orders;multilevel databases;graph algorithms;hierarchically decomposed databases;security;crowns |
629420 | An Example of Deriving Performance Properties from a Visual Representation of Program Execution. | AbstractThrough geometry, program visualization can yield performance properties. We derive all possible synchronization sequences and durations of blocking and concurrent execution for two process programs from a visualization mapping processes, synchronization, and program execution to Cartesian graph axes, line segm... | Introduction
Systems to visualize the execution history collected from a program can help explain what happens
during program execution (e.g., [4, 10, 13, 15]). Visualization systems can lend insight into why a
Supported in part by National Science Foundation grant NCR-9211342.
performance measure, such as program exec... | ray shooting;parallel computation;reachability analysis;computational geometry;visualization;mutual exclusion;performance evaluation;timed progress graphs;petri nets |
629425 | Generalized Algorithm for Parallel Sorting on Product Networks. | AbstractWe generalize the well-known odd-even merge sorting algorithm, originally due to Batcher [2], and show how this generalized algorithm can be applied to sorting on product networks.If G is an arbitrary factor graph with N nodes, its r-dimensional product contains $N^r$ nodes. Our algorithm sorts $N^r$ keys store... | Introduction
Recently, there has been an increasing interest in product networks in the literature. This is
partly due to the elegant mathematical structure of product networks and partly due to the
fact that several well-known networks, such as hypercubes, grids, and tori, are instances of the
family of product networ... | product networks;odd-even merge;algorithms;interconnection networks;sorting |
629430 | Scheduling Data-Flow Graphs via Retiming and Unfolding. | AbstractLoop scheduling is an important problem in parallel processing. The retiming technique reorganizes an iteration; the unfolding technique schedules several iterations together. We combine these two techniques to obtain a static schedule with a reduced average computation time per iteration. We first prove that t... | INTRODUCTION
OW to efficiently and optimally schedule iterative or
recursive algorithms is an important problem in VLSI
high level synthesis and compilers for parallel machines
like VLIW or Data-Flow machines. For example, given a
signal flow graph of any filter (it may have many cycles),
we would like to know how to o... | retiming;loop parallelization;data-flow graphs;parallel processing;scheduling;unfolding |
629432 | A Unified Architecture for the Computation of B-Spline Curves and Surfaces. | AbstractB-Splines, in general, and Non-Uniform Rational B-Splines (NURBS), in particular, have become indispensable modeling primitives in computer graphics and geometric modeling applications. In this paper, a novel high-performance architecture for the computation of uniform, nonuniform, rational, and nonrational B-S... | Introduction
The explosive growth of computer graphics over the last two decades has been greatly facilitated by
impressive hardware innovations: Raster graphics became popular due to the emergence of low-cost
semiconductor memories for the frame buffer. Graphics co-processors and graphics display controllers
designed ... | VLSI architecture;NURBS;graphics;geometric modeling |
629437 | A Practical Approach to Dynamic Load Balancing. | AbstractThis paper presents a cohesive, practical load balancing framework that improves upon existing strategies. These techniques are portable to a broad range of prevalent architectures, including massively parallel machines, such as the Cray T3D/E and Intel Paragon, shared memory systems, such as the Silicon Graphi... | Introduction
A number of trends in computational science and engineering have increased the need for effective
dynamic load balancing techniques. In particular, particle/plasma simulations, which have
recently become more common, generally have less favorable load distribution characteristics
than continuum calculation... | massively parallel computing;dynamic load balancing;diffusion;irregular problems |
629439 | Low Expansion Packings and Embeddings of Hypercubes into Star Graphs. | AbstractWe discuss the problem of packing hypercubes into an n-dimensional star graph S(n), which consists of embedding a disjoint union of hypercubes U into S(n) with load one. Hypercubes in U have from $\lfloor n/2 \rfloor$ to $(n+1)\cdot \left\lfloor {\log_2\,n} \right\rfloor -2^{\left\lfloor {\log_2n} \right \rfloo... | Introduction
The star graph [1] was proposed as an attractive interconnection
network for parallel processing, featuring smaller degree
and diameter than a hypercube [2] of comparable size.
However, the earlier introduction of hypercube networks,
along with their interesting characteristics, has given to such
networks ... | routing;graph embeddings;star graphs;interconnection networks;hypercubes |
629443 | An Efficient Dynamic Scheduling Algorithm for Multiprocessor Real-Time Systems. | AbstractMany time-critical applications require predictable performance and tasks in these applications have deadlines to be met. In this paper, we propose an efficient algorithm for nonpreemptive scheduling of dynamically arriving real-time tasks (aperiodic tasks) in multiprocessor systems. A real-time task is charact... | Introduction
Multiprocessors have emerged as a powerful computing means for real-time applications such as avionic
control and nuclear plant control, because of their capability for high performance and reliability. The
problem of multiprocessor scheduling is to determine when and on which processor a given task ex-
ec... | real-time systems;multiprocessor;dynamic scheduling;parallelizable tasks;resource constraints |
629444 | On Supernode Transformation with Minimized Total Running Time. | AbstractWith the objective of minimizing the total execution time of a parallel program on a distributed memory parallel computer, this paper discusses how to find an optimal supernode size and optimal supernode relative side lengths of a supernode transformation (also known as tiling). We identify three parameters of ... | Introduction
Supernode partitioning is a transformation technique that groups a number of iterations
in a nested loop in order to reduce the communication startup cost. This paper
addresses the problem of finding the optimal grain size and shape of the supernode
transformation so that the total running time, which is t... | distributed memory multicomputer;supernode partitioning;minimizing running time;parallelizing compilers;tiling |
629452 | Power-Aware Localized Routing in Wireless Networks. | AbstractRecently, a cost aware metric for wireless networks based on remaining battery power at nodes was proposed for shortest-cost routing algorithms, assuming constant transmission power. Power-aware metrics, where transmission power depends on distance between nodes and corresponding shortest power algorithms were ... | Introduction
In this paper we consider the routing task, in which a message is to be sent from a source node
to a destination node (in a sensor or ad hoc wireless network). Due to propagation path loss, the
transmission radii are limited. Thus, routes between two hosts in the network may consist of hops
through other h... | routing;power management;wireless networks;distributed algorithms |
629472 | Scalable Stability Detection Using Logical Hypercube. | AbstractThis paper proposes to use a logical hypercube structure for detecting message stability in distributed systems. In particular, a stability detection protocol that uses such a superimposed logical structure is presented, and its scalability is being compared with other known stability detection protocols. The m... | Introduction
Reliable multicast has been recognized as a key feature in many distributed systems, as it
allows reliable dissemination of the same message to a large number of recipients. Conse-
quently, reliable multicast is supported by many middlewares such as group communication
(Isis [5], Horus [35], Transis [10], ... | scalability;distributed systems;reliable multicast;group communication |
629492 | On Time Optimal Supernode Shape. | AbstractWith the objective of minimizing the total execution time of a parallel program on a distributed memory parallel computer, this paper discusses the selection of an optimal supernode shape of a supernode transformation (also known as tiling). We identify three parameters of a supernode transformation: supernode ... | Introduction
Supernode partitioning is a transformation technique
that groups a number of iterations in a nested
loop in order to reduce the communication startup
cost. This paper addresses the problem of selecting
optimal cutting hyperplane directions and optimal
supernode relative side lengths with the objective of
m... | distributed memory multicomputer;minimizing running time;parallelizing compilers;algorithm partitioning;tiling;supernode transformation |
630534 | Scalable Feature Mining for Sequential Data. | Classification algorithms are difficult to apply to sequential examples, such as text or DNA sequences, because a vast number of features are potentially useful for describing each example. Past work on feature selection has focused on searching the space of all subsets of the available features, which is intractable f... | Introduction
Many real world datasets contain irrelevant or redundant attributes. This may be because the data was collected
without data mining in mind, or because the attribute dependences were not known a priori during data collection. It
is well known that many data mining methods like classification, clustering, e... | classification;sequence mining;feature extraction;feature selection |
630575 | Analyzing the Subjective Interestingness of Association Rules. | Association rules are a class of important regularities in databases. They are found to be very useful in practical applications. However, association rule mining algorithms tend to produce a huge number of rules, most of which are of no interest to the user. Due to the large number of rules, it is very difficult for t... | Introduction
The interestingness issue has long been identified as an important problem in data mining. It refers to
finding rules that are interesting/useful to the user, not just any possible rule [e.g., 1, 11, 12, 21, 23,
24, 27, 30]. The reason for its importance is that, in practice, it is all too easy for a data ... | interestingness analysis in data mining;subjective interestingness;association rules |
631019 | The Infeasibility of Quantifying the Reliability of Life-Critical Real-Time Software. | This work affirms that the quantification of life-critical software reliability is infeasible using statistical methods, whether these methods are applied to standard software or fault-tolerant software. The classical methods of estimating reliability are shown to lead to exorbitant amounts of testing when applied to l... | Introduction
The potential of enhanced flexibility and functionality has led to an ever increasing use of digital
computer systems in control applications. At first, the digital systems were designed to perform
the same functions as their analog counterparts. However, the availability of enormous computing
power at a l... | software reliability;life-critical real-time software;software fault tolerance;fault-tolerant software;growth models;fault tolerant computing;real-time systems;statistical methods;multiversion software experiments;safety;reliability |
631027 | Performance Comparison of Three Modern DBMS Architectures. | The introduction of powerful workstations connected through local area networks (LANs) inspired new database management system (DBMS) architectures that offer high performance characteristics. The authors examine three such software architecture configurations: client-server (CS), the RAD-UNIFY type of DBMS (RU), and e... | Introduction
Centralized DBMSs present performance restrictions due to their limited resources. In
the early eighties, a lot of research was geared towards the realization of database ma-
chines. Specialized but expensive hardware and software were used to built complex
systems that would provide high transaction throu... | DBMS architectures;software architecture configurations;RAD-UNIFY type;design rationales;database management systems;simulation models;performance evaluation;client-server;functional components;workstations;simulation results;local area networks;software engineering |
631036 | A Formal Analysis of the Fault-Detecting Ability of Testing Methods. | Several relationships between software testing criteria, each induced by a relation between the corresponding multisets of subdomains, are examined. The authors discuss whether for each relation R and each pair of criteria, C/sub 1/ and C/sub 2/, R(C/sub 1/, C/sub 2/) guarantees that C/sub 1/ is better at detecting fau... | Introduction
Over the last several years, researchers have defined a wide variety of software testing
techniques, studied their properties, and built tools based on some of them. Recently,
there has been increasing interest in the question of how techniques compare to one
another in terms of their ability to expose fau... | fault-detecting ability;software testing criteria;program testing;subdomains;system recovery;multisets;formal analysis;subsumption relation;probabilistic measures |
631040 | A New Approach to Version Control. | A method for controlling versions of software and other hierarchically structured entities is presented. Using the variant structure principle, a particular version of an entire system is formed by combining the most relevant existing versions of the various components of the system. An algebraic version language that ... | Introduction
Software systems undergo constant evolution. Specifications change, improvements are
made, bugs are fixed, and different versions are created to suit differing needs. As these
changes are made, families of systems arise, all very similar, yet different. Handling such
changes for a large system is a non-tri... | numbered series;divergent variants;programming environment;configuration management;formal languages;version control;lattice least upper bound;world semantics;formal logic;subversions;hierarchically structured entities;modular C programs;LEMUR;intensional logic;join operation;algebraic version language;programming envi... |
631068 | An Experimental Comparison of the Effectiveness of Branch Testing and Data Flow Testing. | An experiment comparing the effectiveness of the all-uses and all-edges test data adequacy criteria is discussed. The experiment was designed to overcome some of the deficiencies of previous software testing experiments. A large number of test sets was randomly generated for each of nine subject programs with subtle er... | Introduction
Considerable effort in software testing research has focussed on the development of software
test data adequacy criteria, that is, criteria that are used to determine when software
has been tested "enough", and can be released. Numerous test data adequacy criteria
have been proposed, including those based ... | regression analysis;program testing;branch testing;error exposing ability;all-edges test data adequacy criteria;data flow testing;software testing experiments;definition-use associations;executable edges;all-uses adequate test sets;errors |
631072 | Exception Handlers in Functional Programming Languages. | Constructs for expressing exception handling can greatly help to avoid clutter in code by allowing the programmer to separate the code to handle unusual situations from the code for the normal case. The author proposes a new approach to embed exception handlers in functional languages. The proposed approach discards th... | Introduction
Functional Programming languages (FP) [1] describe algorithms
in a clear, concise, and natural way. For any programming
language this is a highly desirable feature. In FP
programs are constructed using primitive and user-defined
functions as building blocks, and functionals or program-
forming operations a... | exception handling;programmer;functional languages;functional programming;high level languages;terminate;referential transparency;input object;programming theory;commutativity properties;implementation restriction;resume |
631084 | Provable Improvements on Branch Testing. | This paper compares the fault-detecting ability of several software test data adequacy criteria. It has previously been shown that if C/sub 1/ properly covers C/sub 2/, then C/sub 1/ is guaranteed to be better at detecting faults than C/sub 2/, in the following sense: a test suite selected by independent random selecti... | Introduction
Although a large number of software testing techniques have been proposed during the
last two decades, there has been surprisingly little concrete information about how effectively
they detect faults. This is true both in the case of theoretical analyses and
Author's address: Computer Science Dept., Polyte... | fault-detecting ability;program testing;condition-coverage techniques;branch testing;software testing;software test data adequacy;programming theory;data flow testing;program debugging;independent random selection;probabilistic measure;test suite;mutation testing |
631115 | Using Term Rewriting to Verify Software. | This paper describes a uniform approach to the automation of verification tasks associated with while statements, representation functions for abstract data types, generic program units, and abstract base classes. Program units are annotated with equations containing symbols defined by algebraic axioms. An operation's ... | Introduction
Many different methods have been used to annotate software and prove properties about it. Fewer
attempts have been made to adapt a single notation to a variety of different annotation tasks and
explore the interactions between the types of tasks, properties of the specifications, and demands of
verificatio... | term rewriting;software tools;abstract data types;algebraic axioms;generic program units;representation functions;program verification;convergence;sufficient completeness;structural induction;boyer-moore prover;rewriting systems;while statements;verification tasks;abstract base classes;mechanical assistance;theorem pro... |
631132 | Certification of Software Components. | Reuse is becoming one of the key areas in dealing with the cost and quality of software systems. An important issue is the reliability of the components, hence making certification of software components a critical area. The objective of this article is to try to describe methods that can be used to certify and measure... | Introduction
Object-oriented techniques make it possible to develop components in
general, and to develop reusable components in particular. These
components must be certified regarding their properties, for example
their reliability.
A component developed for reuse must have reliability measures
attached to it, based... | software reliability;software cost;software reuse;software quality;failure statistics;usage testing;usage modelling technique;hypothesis certification model;usage profile;usage modelling;software reusability;software cost estimation;software component certification |
631135 | A Characterization of the Stochastic Process Underlying a Stochastic Petri Net. | Stochastic Petri nets (SPN's) with generally distributed firing times can model a large class of systems, but simulation is the only feasible approach for their solution. We explore a hierarchy of SPN classes where modeling power is reduced in exchange for an increasingly efficient solution. Generalized stochastic Petr... | Introduction
A BOUT one decade ago, Molloy [1], Natkin [2], and
Symons [3] independently proposed associating exponentially
distributed firing delays to the transitions of a
Petri net. Generalized stochastic Petri nets (GSPNs), introduced
by Ajmone Marsan, Balbo, and Conte in [4], relax
this condition by allowing "imme... | PH-type distributions;embedded Markov chain;stochastic Petri nets;stochastic Petri net;semiMarkovian stochastic Petri nets;stochastic process;distributed firing times;simulation;deterministic Petri nets;SPN classes;modeling power;stochastic processes;markov processes;timed Petri nets;state discretization;continuous-tim... |
631150 | Warm Standby in Hierarchically Structured Process-Control Programs. | We classify standby redundancy design space in process-control programs into the following three categories: cold standby, warm standby, and hot standby. Design parameters of warm standby are identified and the reliability of a system using warm standby is evaluated and compared with that of hot standby. Our analysis i... | Introduction
Process-control programs, such as those for controlling
manufacturing systems, can often be organized in a multi-level
hierarchical control structure where higher level processes
formulate long-term control strategies, e.g., optimizing
resource management, whereas lower level processes
perform real-time co... | software reliability;process computer control;hierarchically structured process-control programs;software maintenance;burst hardware failures;redundancy;warm standby;process-control programs;simulated chemical batch reactor system;system reliability;long-lived unmaintainable systems;hot standby;cold standby;computer in... |
631158 | Measures of the Potential for Load Sharing in Distributed Computing Systems. | In this paper we are concerned with the problem of determining the potential for load balancing in a distributed computing system. We define a precise measure, called the Number of Sharable Jobs, of this potential in terms of the number of jobs that can usefully be transferred across sites in the system. Properties of ... | Introduction
In a distributed system, statistical fluctuations in arrival and service patterns across the various
sites cause imbalances in load where one or more sites may be operating much below capacity
and others may simultaneously be overloaded. Livny and Melman [4] showed that in a
distributed system consisting o... | distributed systems;load sharing;job sharing coefficient;sharable jobs |
631167 | Guaranteeing Real-Time Requirements With Resource-Based Calibration of Periodic Processes. | This paper presents a comprehensive design methodology for guaranteeing end-to-end requirements of real-time systems. Applications are structured as a set of process components connected by asynchronous channels, in which the endpoints are the systems external inputs and outputs. Timing constraints are then postulated ... | Introduction
Most real-time systems possess only a small handful of inherent timing constraints which will "make
or break" their correctness. These are called end-to-end constraints, and they are established on
the systems' external inputs and outputs. Two examples are:
(1) Temperature updates rely on pressure and temp... | design methodology;non-linear optimization;end-to-end timing constraints;real-time;static priority scheduling;constraint solving |
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